Preimplantation genetic testing using comprehensive genomic copy number analysis is beneficial for balanced translocation carriers.

Balanced chromosomal translocation is one of chromosomal variations. Carriers of balanced chromosomal translocations have an increased risk of spontaneous miscarriage. To avoid the risk, preimplantation genetic testing (PGT) using comprehensive genomic copy number analysis has been developed. This study aimed to verify whether and how embryos from couples in which one partner is a balanced translocation carrier have a higher ratio of chromosomal abnormalities. A total of 894 biopsied trophectoderms (TEs) were obtained from 130 couples in which one partner was a balanced translocation carrier (Robertsonian translocation, reciprocal translocation, or intrachromosomal inversion) and grouped as PGT-SR. Conversely, 3269 TEs from 697 couples who experienced recurrent implantation failure or recurrent pregnancy loss were included in the PGT-A group. The transferable blastocyst ratio was significantly lower in the PGT-SR group, even when bias related to the sample number and patient age was corrected. Subgroup analysis of the PGT-SR group revealed that the transferable blastocyst ratio was higher in the Robertsonian translocation group. Because the PGT-SR group had a higher proportion of untransferable embryos than the PGT-A group, PGT using comprehensive genomic copy number analysis was more beneficial for balanced translocation carriers than for infertility patients without chromosomal translocations. The frequencies of de novo aneuploidies were further analyzed, and the frequency in the PGT-SR group was lower than that in the PGT-A group. Therefore, we could not confirm the existence of interchromosomal effects in this study.

Endometrial preparation and maternal and obstetrical outcomes after frozen blastocyst transfer.

BACKGROUND: Two types of endometrial preparation protocols are used for frozen embryo transfers in current practice: hormone replacement and the natural cycle. Endometrial preparation in the natural cycle reportedly increases the chances of live birth and decreases early pregnancy loss compared with that in the hormone replacement cycle. However, the influence of endometrial preparation on maternal and neonatal health remains unclear. OBJECTIVE: This study aimed to investigate whether the differences between hormone replacement cycle and natural cycle influence perinatal outcomes and risk of congenital anomalies in frozen-thawed blastocyst transfer fetuses or births. STUDY DESIGN: Perinatal outcomes and congenital abnormalities were compared between the natural and hormone replacement cycles. According to the timing of ovulation, frozen-thawed blastocyst transfers in the natural cycle were classified into 2 patterns: on day 4.5 (ovulation 4.5) or day 5 (ovulation 5.0) after ovulation. When the serum luteinizing hormone level was not increased on the day of the trigger, a single vitrified-warmed blastocyst transfer was performed on day 7 after the trigger (ovulation 5.0). When the luteinizing hormone level was slightly increased on the day of trigger, single vitrified-warmed blastocyst transfer was performed on day 6 after the trigger (ovulation 5.0). In total, 67,018 cycles (ovulation 4.5, 29,705 cycles; ovulation 5.0, 31,995 cycles; hormone replacement, 5318 cycles) of frozen-thawed blastocyst transfer between January 2008 and December 2017 at Kato Ladies Clinic were retrospectively analyzed. During the study period, embryo cryopreservation was performed using a vitrification method in all cycles. RESULTS: Hormone replacement cycles were associated with a higher occurrence of hypertensive disorders of pregnancy (adjusted odds ratio, 2.16; 95% confidence interval, 1.66-2.81) and placenta accreta (adjusted odds ratio, 4.14; 95% confidence interval, 1.64-10.44) compared with the natural cycle. The risks of cesarean delivery (adjusted odds ratio, 1.93; 95% confidence interval, 1.78-2.18), preterm birth (adjusted odds ratio, 1.55; 95% confidence interval, 1.25-1.93), and low birthweight (adjusted odds ratio, 1.42; 95% confidence interval, 1.18-1.73) were also higher for hormone replacement cycles. No significant difference in the risk of congenital anomalies was observed between the 2 cycles. CONCLUSION: The risk of hypertensive disorders of pregnancy, placenta accreta, cesarean delivery, preterm delivery, and low birthweight was higher in hormone replacement cycles than in natural cycles, whereas the risk of congenital anomalies was similar between both cycles. Further follow-up is needed to investigate these risks and to explore alternative endometrial preparation methods.

Perinatal outcomes and congenital anomalies associated with letrozole and natural cycles in single fresh cleaved embryo transfers: A single-center, 10-year cohort study.

Objective: To investigate and compare the safety of letrozole and natural cycles in fresh early embryo transfers. Design: A retrospective cohort study. Setting: A large fertility treatment center. Patients: Women who underwent natural and letrozole cycles during fresh early embryo transfer at Kato Ladies Clinic between January 2008 and December 2017. Interventions: None. Main Outcome measures: Perinatal complications and congenital anomalies. Results: No significant differences were observed in pregnancy complications, gestational age, birth weight, small for gestational age, large for gestational age, and congenital anomalies between the the women who underwent natural and letrozole cycles. Conclusions: The perinatal outcomes and congenital anomaly rates associated with letrozole and natural cycles in fresh early embryo transfers were comparable. Therefore, our data support the safe use of letrozole in fresh early embryo transfers in assisted reproductive technology.

Maternal and obstetric outcomes are influenced by developmental stage and cryopreservation of transferred embryos after clomiphene citrate-based minimal stimulation IVF.

STUDY QUESTION: Is the embryo transfer (ET) method associated with maternal and perinatal outcomes after minimal stimulation IVF using clomiphene citrate (CC)? SUMMARY ANSWER: The incidence of pregnancy complications and adverse perinatal outcomes was influenced by the developmental stage (cleavage versus blastocyst stages) and cryopreservation (fresh versus vitrified) of the transferred embryos. WHAT IS KNOWN ALREADY: Pregnancies resulting from IVF are associated with higher risks of adverse perinatal outcomes compared to natural conceptions; therefore, the next focus in reproductive medicine should be to assess whether these increased risks are attributable to IVF. Pregnancy complications and perinatal outcomes should be considered in addition to pregnancy outcomes when selecting the ET method, however, studies that describe the influence of transfer methods on perinatal and maternal outcomes are limited. STUDY DESIGN SIZE DURATION: This study retrospectively analysed a large single-centre cohort. The clinical records of 36 827 women who underwent oocyte retrieval (during a CC-based minimal stimulation cycle) followed by their first ET at the fertility treatment centre between January 2008 and December 2017 were retrospectively analysed. The patients underwent a single fresh cleavage-stage ET (SFCT), single vitrified-warmed cleavage-stage ET (SVCT) or single vitrified-warmed blastocyst transfer (SVBT). This study only included one cycle per patient. PARTICIPANTS/MATERIALS SETTING METHODS: Oocyte retrieval was performed following CC-based minimal ovarian stimulation. The embryos were transferred 2-3 days after retrieval or vitrified at the cleavage or blastocyst stage. The vitrified embryos were then warmed and transferred within the natural cycles. Pregnancy complications and perinatal outcomes were stratified according to the transfer methods used. Multivariate logistic regression analysis was performed to evaluate the effect of ET methods on the prevalence of pregnancy complications and congenital anomalies. MAIN RESULTS AND THE ROLE OF CHANCE: The rates of clinical pregnancy and delivery were significantly different among the groups. We analysed pregnancy complications in 7502 singleton births (SFCT, 3395 cycles; SVCT, 586 cycles; and SVBT, 3521 cycles). Multivariate logistic regression analysis revealed that the adjusted odds ratio (AOR) for hypertensive disorders in pregnancy was significantly lower in the SVBT group than in the SFCT group [AOR, 0.72; 95% CI, 0.56-0.92]. The AOR for low-lying placenta was lower in the SVBT group than in the SFCT group (AOR, 0.34; 95% CI, 0.19-0.60). The AOR for placenta previa was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.21; 95% CI, 0.07-0.58 versus AOR, 0.53; 95% CI, 0.38-0.75, respectively). A total of 7460 follow-up data on neonatal outcomes was analysed. The AOR for preterm delivery was lower in the SVBT group than in the SFCT group (AOR, 0.78; 95% CI, 0.64-0.94). The AOR for low birthweight was significantly lower after SVCT and SVBT than after SFCT (AOR, 0.68; 95% CI, 0.46-0.98 versus AOR, 0.57; 95% CI, 0.48-0.66, respectively). The AOR for small for gestational age was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.68; 95% CI, 0.46-0.98 versus AOR, 0.44; 95% CI, 0.36-0.55, respectively). The AOR for large for gestational age babies was higher in the SVBT group than in the SFCT group (AOR, 1.88; 95% CI, 1.62-2.18). The incidence of each congenital anomaly was similar among the groups. LIMITATIONS REASONS FOR CAUTION: The study data were collected through self-reported parental questionnaires on maternal and neonatal outcomes. Our findings were not compared with the incidence of pregnancy complications and congenital anomalies in natural pregnancies. Furthermore, this study was retrospective in nature; therefore, further studies are required to ascertain the generalizability of these findings to other clinics with different protocols and/or different patient demographics. WIDER IMPLICATIONS OF THE FINDINGS: This study demonstrated reassuring outcomes for SVBT (in terms of a lower incidence of pregnancy complications) compared to SFCT. Our findings provide valuable knowledge that will help improve perinatal and maternal outcomes in CC-based stimulation and inform couples of the possible benefits and risks of each type of ET method. STUDY FUNDING/COMPETING INTERESTS: This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Reproductive outcomes following preimplantation genetic diagnosis using fluorescence in situ hybridization for 52 translocation carrier couples with a history of recurrent pregnancy loss.

Forty-six reciprocal and six Robertsonian translocation carrier couples who experienced recurrent pregnancy loss underwent fluorescence in situ hybridization-based preimplantation genetic diagnosis (PGD) for the presence of the two translocated chromosomes. Out of 52 couples, 17 (33%) were undergoing infertility treatment. In total, 239 PGD cycles as oocyte retrieval (OR) were applied. The transferrable rate of negatively diagnosed embryos at the cleavage stage was 26.3%; 71 embryos were transferred as single blastocysts. The clinical pregnancy rate per transfer was 60.6%. We obtained 41 healthy live births with 3 incidences of miscarriage (7.0%). The average cumulative live birth rate was 76.9% during 4.6 OR cycles using a mild ovarian stimulation strategy. The outcomes were classified into four groups based on carrier gender and maternal age (young (<38 years) or advanced). PGD was performed for 52 couples of which the average number of OR cycles was 4.1, 2.1, 6.7 and 4.5 in young female and male carriers and female and male carriers of advanced age; the live birth rate for a primiparity was 77.8, 72.7, 66.7 and 50.0% in those groups. These results suggest that the final live birth rate might be influenced by maternal age regardless of the gender of the carrier.

Neonatal outcome and birth defects in 6623 singletons born following minimal ovarian stimulation and vitrified versus fresh single embryo transfer.

OBJECTIVE: To compare neonatal outcome between children born after vitrified versus fresh single-embryo transfer (SET). STUDY DESIGN: Retrospective, single-centre cohort study of 6623 delivered singletons following 29,944 single-embryo transfers. Patients underwent minimal ovarian stimulation/natural cycle IVF followed by SET of fresh or vitrified-warmed (using Cryotop, Kitazato) cleavage-stage embryos or blastocysts. Outcome measures were gestational age at delivery, birth weight, birth length, low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA) infants, perinatal mortality and minor/major birth defects (evaluated by parent questionnaire). RESULTS: Gestational age (38.6 ± 2 versus 38.7 ± 1.9 weeks) and preterm delivery rate (6.9% versus 6.9%, aOR: 0.96 95%CI: 0.76-1.22) in singletons born after the transfer of vitrified embryos were comparable to those born after the transfer of fresh embryos. Children born after the transfer of vitrified embryos had a higher birth weight (3028 ± 465 versus 2943 ± 470 g, p<0.0001) and lower LBW (8.5% versus 11.9%, aOR: 0.65 95%CI: 0.53-0.79) and SGA (3.6% versus 7.6% aOR: 0.43 95%CI: 0.33-0.56) rates. Total birth defect rates (including minor anomalies) (2.4% versus 1.9%, aOR: 1.41 95%CI: 0.96-2.10) and perinatal mortality rates (0.6% versus 0.5%, aOR: 1.02 95%CI: 0.21-4.85) were comparable between the vitrified and fresh groups. CONCLUSIONS: Vitrification of embryos/blastocysts did not increase the incidence of adverse neonatal outcomes or birth defects following single embryo transfer.

Ectopic expression of mitochondria endonuclease Pnu1p from Schizosaccharomyces pombe induces cell death of the yeast.

Endonuclease G (EndoG) is a mitochondrial non-specific nuclease that is highly conserved among the eukaryotes. Although the precise role of EndoG in mitochondria is not yet known, the enzyme is released from the mitochondria and digests nuclear DNA during apoptosis in mammalian cells. Schizosaccharomyces pombe has an EndoG homolog Pnu1p (previously named SpNuc1) that is produced as a precursor protein with a mitochondrial targeting sequence. During the sorting into mitochondria the signal sequence is cleaved to yield the functionally active endonuclease. From the analogy to EndoG, active extramitochondrial Pnu1p may trigger cell killing by degrading nuclear DNA. Here, we tested this possibility by expressing a truncated Pnu1p lacking the signal sequence in the extramitochondrial region of pnu1-deleted cells. The truncated Pnu1p was localized in the cytosol and nuclei of yeast cells. And ectopic expression of active Pnu1p led to cell death with fragmentation of nuclear DNA. This suggests that the Pnu1p is possibly involved in a certain type of yeast cell death via DNA fragmentation. Although expression of human Bak in S. pombe was lethal, Pnu1p nuclease is not necessary for hBak-induced cell death.